Avaliação da interação de huminas e torta de filtro com íons Pb(II), Ca(II) e Mg(II)

Abstract

Natural substances that interact with inorganic pollutants, such as potentially toxic metals, are of great interest in environmental chemistry. Some organic waste, such as filter cake and humin, has been discarded in the environment, with few studies on its remedial potential. Filter cake is one of the residues of the sugar-alcohol industry and humin is the poorly soluble fraction of the main form of organic matter distributed in terrestrial systems. This work aimed to evaluate the characteristics and behavior of filter cake and humin samples by metal species (Pb (II), Mg (II) and Ca (II)). The objective of this study was to evaluate the influence of the organic and inorganic fraction of humin on the adsorption of Pb (II) ions, the humin was extracted from a arable soil located in Arapiraca / AL (HA) and from a soil rich in organic matter located near the River Pratagi Maceió / AL (HM). Characterizations were made by Spectroscopy in the Infrared Region with Fourier Transform - FTIR and scanning electron microscopy - SEM, and the adsorption studies were carried out to measure the affinity of the samples by the contaminant and the metals were determined by Reduction Solution Chronopotentiometry in the Nernstiano Equilibrium and in the Absence of Gradients (AGNES). It verified the influence of pH on the interaction process between macronutrients and humins extracted from soils with different levels of organic matter. The characterizations were performed using spectroscopy in the visible ultraviolet region, UV-Vis (Ratio E4 / E6) and elementary analysis (C / H ratio). The determination of the metals were performed using atomic emission spectrometry by microwave plasma - MP-AES. The filter cake of three different states (Alagoas, Pernambuco and São Paulo), titrated respectively by TFAL, TFPE and TFSP, and the release of macronutrients (Ca (II) and Mg (II)) were characterized as a function of pH and (C / H and C / N ratio), the macronutrient release studies (Ca (II) and Mg (II)), the metals were determined by means of UV-Vis (Ratio E4 / E6) and elemental analysis MP-AES. Studies were carried out to verify the complexing capacity of the samples studied by Pb (II). It was noticeable through the analysis that HM presented a higher content of organic matter - MO (8.60%) compared to the HA (3.60%), a result expected by HM being from a soil rich in OM, The results were similar to those of TF-AL and TF-PE, which showed a high MO presence and a higher degree of humification, compared to TF-SP. Therefore, E4 / E6, C / H and C /N, presented more significant reasons for this work, corroborating with FTIR, SEM and adsorption studies. Up to now the results have shown promise for the use of calcination of humins and may be a viable strategy for the application of this material as a potentially toxic metal adsorbent and for the use of filter and humin cakes as natural organic fertilizers for subsequent enrichment with nutrients and application in real sy